Tashkent Chemical Technological Institute COFFEE Group:43-17 Done by: Mirkobilov M Received by: Rakhmonova M

Introduction Coffee is enjoyed by millions of people around the world and its components have been extensively researched. The sensory experience when consuming a cup of coffee is one of the key aspects of the drink, providing unique aromas, tastes and flavours. The type of coffee, level of roasting and preparation method all impact the overall sensory experience of coffee. This topic reviews the sensory qualities of coffee, the factors that influence these and the multisensory experience that contributes to the overall enjoyment of consuming a cup of coffee.

Aroma, taste and flavour Aroma, taste and flavour are closely connected concepts, however they have distinct definitions. Aroma is defined as an odour, sensed through the nose and retronasally, and also through the back of the mouth where the nasal and mouth cavities are interlinked. Taste is the sense experienced by the tongue and describes sensations of saltiness, sweetness, sourness, bitterness or umami. Flavour is defined as a combination of both aroma and taste. Taste and aroma are closely associated with each other and are both perceived by processes within the limbic brain areas that participate in emotion. Aroma plays a particular role in evoking thoughts and emotions that stem from previous experiences and memories 1. Sensory experts describe the taste and aroma of coffee in great detail and are able to differentiate between different origins of coffee beans, levels of roast and preparation methods.

Aroma and flavour: composition of coffee Aroma is one of the first senses experienced when preparing or consuming a coffee beverage. However, being largely composed of ‘volatile compounds’ that easily evaporate at room temperature, aroma is also one of the most variable components of the sensory experience 2. Approximately 850 volatile compounds have been identified that are associated with flavour in coffee. However, a small proportion of these (approximately 40 volatile compounds) with low odour thresholds and/or high concentrations are known to be the main contributors to coffee aroma 3,4. The main volatile compounds in coffee include carbonyl, sulfur alicyclic aromatic benzenoid and heterocyclic compounds 5. Further information on the composition of coffee can be found here.here

Multi-sensory interactions Reaching all the senses The full sensory experience spans the period of preparation through to consumption. It begins with the coffee aroma experienced when opening the container, to the visual cues seen when preparing the coffee, including the colour of the coffee and the presence of crema or coffee foam. Arguably, the sensory experience of enjoying a cup of coffee might even start upon entering a coffee shop and hearing the sound of a machine as research suggests that sound plays an essential role in customers’ daily interactions with products, often influencing their cognitive processes, emotions, and behaviour 12. Finally, both the aroma and taste of coffee contribute to the experience of consumption. The addition of milk or sugar to a cup of coffee, not only alters the flavour profile but may also impact aroma, with research suggesting reduced levels of aroma are experienced when additions to coffee are included 13. Researchers have also suggested that lower fat, homogenized milks, with correspondingly smaller fat globules, can induce a more intense coffee related taste and aroma when compared to whole milk 14.

Where Coffee Grows The coffee tree is a tropical evergreen shrub (genus Coffea) and grows between the Tropics of Cancer and Capricorn. The two most commercially important species grown are varieties of Coffea arabica (Arabicas) and Coffea canephora (Robustas). The average Arabica plant is a large bush with dark-green oval leaves. The fruits, or cherries, are rounded and mature in 7 to 9 months; they usually contain two flat seeds, the coffee beans. When only one bean develops it is called a peaberry. Robusta is a robust shrub or small tree that grows up to 10 metres high. The fruits are rounded and take up to 11 months to mature; the seeds are oval in shape and smaller than Arabica seeds. Ideal average temperatures range between 15 to 24ºC for Arabica coffee and 24 to 30ºC for Robusta, which can flourish in hotter, harsher conditions. Coffee needs an annual rainfall of 1500 to 3000 mm, with Arabica needing less than other species. Whereas Robusta coffee can be grown between sea-level and about 800 metres, Arabica does best at higher altitudes and is often grown in hilly areas.

Initial Processing After harvesting the next step is to remove the coffee seeds from the ripe fruit and dry them. This can be done in two ways: the dry and the wet methods. The Dry Method The dry or ‘natural’ method involves drying the whole cherry. It is the oldest, simplest method and requires little machinery. The harvested cherries are sorted and cleaned, by hand, to remove unripe, overripe and damaged cherries as well as any dirt, soil, twigs and leaves. This can also be done by floating the cherries in water. The Wet Method The wet method requires the use of special equipment and the availability of water. As with the dry method, the ripe cherries are first cleaned. They are then pulped by a machine that squeezes the cherries so that the flesh and the skin are separated from the beans. The beans are left with a slippery outer skin (the mucilage) and a parchment covering..

Different drinks The coffee we drink is made from roast and ground coffee prepared in different ways: Filter or drip coffee is made by putting finely-ground coffee in a paper or reusable cone-shaped unit. Nearly-boiling water is then poured on top. The brew filters through the unit into a pot or mug and is ready to drink. The coffee grounds remain in the cone. These days, this is mostly done by electric filter coffee machines. The plunger or cafetiere TM method is made from coarsely ground coffee placed in a pot and hot water added to the grounds. The brew is stirred and left to steep for three to five minutes. The plunger is then pushed down to separate the coffee grounds from the coffee infusion. Espresso machines force hot water under pressure through very finely ground and compacted coffee into the cups below. This enables significant aroma and flavour to be extracted with low quantities of water. Espresso coffee also usually has a top layer of crema, which is a fine and creamy foam.

Advantages – regulates the level of blood pressure and positively affects blood pressure and positively affects blood vessels. Coffee is known as an excellent antioxidant that stimulates brain activity. Disadvantages – just cup of coffee disturbs sleep at night because our body needs 8 hour to process the caffeine from the coffee itself. Therefore, even though we love it as a morning ritual, we need to avoid drinking coffee at night as much as possible.

PLAN: 1. INTRODUCTION 2. BODY: GENERAL INFORMATION AROMA, TEST AND FLAVOUR 3. CONCLUSION